Paterson's Worm,

A description of a mathematical idealization of the feeding pattern of a kind of worm is given. Certain prehistoric worms fed on sediment in the mud at the bottom of ponds. For efficiency, they would not retrace paths which had already been traveled, since little food was left there. Yet food probably occurred in patches, so it was desirable to stay near previous trails. Worms had innate rules regarding how close to eaten paths to stay, how far to go before turning around, how sharp a turn to make, etc. These rules varied from species to species, and paleontologists can trace the development of species and determine the similarity of different species by comparing fossil records of worm tracks. Paths of worms are modelled through pattern recognition. Modified author abstract